What Happens If You Hit a Gas Main or Cable? (UK Guide)

Introduction

Striking an underground service is one of those incidents that can go from “minor mistake” to “major emergency” in seconds. A damaged gas main can leak and ignite. A cut electricity cable can cause severe injury, fires, and power outages. Even telecoms and fibre strikes can shut down businesses and trigger costly claims.

This guide explains what typically happens if you hit a gas main or cable in the UK, what to do immediately, what the legal and financial consequences can look like, and how to reduce the risk on future jobs.

First: what counts as a “gas main” or “cable”?

On most sites, “services” means any underground utility, including:

• Gas pipes (mains and service pipes)
• Electricity cables (low voltage and high voltage)
• Water mains and service pipes
• Sewer and drainage
• Telecoms and fibre

Gas and electricity are usually the highest-risk because of explosion, fire, and electrocution risk.

What happens if you hit a gas main?

1) You may not see the danger straight away

A strike can cause:

• A visible break with a loud “hiss”
• A small crack or pinhole leak
• Damage to protective coatings that later leads to corrosion

Even a small leak can build up gas in a trench, duct, or nearby building.

2) The immediate risks are serious

If gas is escaping, the main risks include:

• Explosion if gas finds an ignition source
• Fire in the trench or nearby property
• Asphyxiation in confined spaces
• Public evacuation and emergency response costs

3) The network operator will attend and make safe

In the UK, the gas emergency service is typically reached via the National Gas Emergency number 0800 111 999. The operator will usually:

• Isolate the supply (where possible)
• Ventilate and monitor gas levels
• Repair or replace the damaged section
• Coordinate with emergency services if needed

If the incident affects a wider area, you may see road closures, traffic management, and a larger response.

What happens if you hit an electricity cable?

1) The danger can be immediate and invisible

Electricity strikes can cause:

• Arc flash and burns
• Electric shock
• Fire
• Damage that later fails (delayed faults)

High voltage cables can be fatal even without direct contact, depending on conditions.

2) Power outages and third-party losses can follow

A single cable strike can knock out:

• Nearby homes
• Shops and offices
• Industrial sites
• Traffic lights and public infrastructure

That can trigger claims for:

• Spoiled stock (e.g., refrigeration)
• Business interruption
• Data loss and system downtime

3) The Distribution Network Operator (DNO) will respond

The local DNO will attend to isolate, test, and repair. You may also need to coordinate with the principal contractor, site manager, and any permit-to-dig controls.

What to do immediately (step-by-step)

If you hit a gas main or cable, the priorities are life safety, then making the area safe, then reporting.

Step 1: Stop work and shut down equipment

• Stop excavation immediately.
• Turn off plant and tools if safe to do so.
• Do not attempt to move the damaged service.

Step 2: Keep people away

• Clear the area.
• Set up a safe exclusion zone.
• Keep members of the public away if you’re near a road or footpath.

Step 3: For a gas strike, remove ignition sources

• No smoking.
• Avoid using phones close to the leak if you suspect a significant gas release.
• Do not start vehicles or generators near the area.

Step 4: Call the right emergency contact

• Gas: call 0800 111 999.
• Electricity: contact the local DNO (or call 105 for power cut and electricity network issues).
• If there is immediate danger to life, call 999.

Step 5: Do not try to repair it yourself

Even if you think you can “patch it up”, do not. Repairs must be handled by the relevant network operator or an authorised contractor.

Step 6: Report internally and preserve evidence

• Inform the site supervisor/principal contractor.
• Record what happened: time, location, plant used, depth, photos (from a safe distance).
• Keep copies of permits, drawings, and risk assessments.

Who is liable if you hit a gas main or cable?

Liability depends on the facts, but common drivers include:

• Failure to use utility plans (or not obtaining them)
• Poor scanning practices (CAT and Genny not used, or used incorrectly)
• No trial holes or unsafe digging methods
• Inadequate supervision
• Rushing the job or ignoring permit-to-dig controls
• Incorrect or outdated plans supplied by others

Contractor vs subcontractor vs principal contractor

On many projects, multiple parties may share responsibility:

• The groundworks contractor doing the excavation
• A subcontractor operating the plant
• The principal contractor controlling site systems and permits
• The client or designer if information was missing or incorrect

In practice, claims often focus on who had control of the work and whether reasonable precautions were taken.

What costs can you face?

Even when nobody is hurt, the financial impact can be significant.

Direct costs

• Emergency call-out and repair charges
• Traffic management and road closures
• Reinstatement of surfaces
• Replacement of ducts, joints, and fittings

Indirect costs

• Project delays and liquidated damages
• Reputational damage
• Increased insurance premiums
• Time spent on investigations and reporting

Third-party claims

• Property damage (fire, explosion, electrical damage)
• Injury claims
• Business interruption claims from affected businesses
• Claims from utilities for network disruption

Do you have to report it under RIDDOR?

RIDDOR reporting depends on the outcome. If the incident results in a specified injury, over-seven-day injury, or a dangerous occurrence, it may be reportable.

A cable strike that causes an explosion, fire, or serious injury can fall into reportable categories. If in doubt, get competent H&S advice and document your decision-making.

What does your insurance need to cover?

If you work in groundworks, construction, utilities, or civil engineering, hitting services is a key exposure. The right insurance won’t stop the incident, but it can protect your business from the financial hit.

Common covers that may respond (depending on policy terms):

• Public Liability: third-party injury or property damage
• Employers’ Liability: injury to employees
• Contractors’ All Risks (CAR): damage to contract works (and sometimes existing property, depending on cover)
• Plant and Tools: damage to owned/hired-in plant
• Professional Indemnity (where design/advice is involved)
• Legal Expenses: support with disputes and defence costs

Important: many policies have conditions around risk management, hot works, and underground services. If you regularly excavate, it’s worth checking whether your policy has specific endorsements or exclusions.

How to reduce the risk on future jobs

1) Get the right plans and confirm they’re current

• Obtain utility drawings before work starts.
• Treat plans as guidance, not a guarantee.
• Confirm dates and revision numbers.

2) Use a permit-to-dig system

A simple permit-to-dig process helps ensure:

• Plans are reviewed
• Scanning is completed
• Trial holes are dug
• Safe digging methods are followed

3) Scan properly (and understand limitations)

CAT and Genny scanning can help locate services, but it’s not perfect. Factors like depth, soil conditions, and non-metallic services can reduce accuracy.

4) Use trial holes and hand digging in high-risk areas

Where services are suspected:

• Dig trial holes carefully
• Use insulated tools where appropriate
• Expose and support services before machine excavation nearby

5) Brief the team and supervise the work

Toolbox talks and competent supervision matter, especially with new starters or agency labour.

6) Plan for emergencies

Have a simple site plan for:

• Emergency numbers
• Evacuation routes
• Who isolates plant
• Who meets the network operator

Common myths that cause trouble

• “The plans were wrong, so we’re not responsible.” Plans can be wrong, but you still need to take reasonable precautions.
• “It was only a small nick.” Small damage can become a big failure later.
• “We can tape it up and carry on.” Unauthorised repairs can make liability worse.

FAQs

What should I do if I smell gas after digging?

Stop work, clear the area, remove ignition sources, and call 0800 111 999. Do not try to find the leak by digging further.

What happens if I hit a cable and there’s no power cut?

There can still be damage that fails later. Stop work and report it so the network operator can test and make safe.

Can I be charged for the repair?

Often yes, particularly if the utility or their contractor believes reasonable precautions were not taken. The exact approach varies by operator and circumstances.

Will my insurance cover it?

It depends on your policy and the facts. Public liability is often the starting point, but underground services claims can involve exclusions, excesses, or special conditions.

How long do repairs take?

It varies. Some repairs are completed in hours; others require isolation, specialist joints, excavation, and reinstatement that can take days.

Conclusion: treat service strikes as emergencies

If you hit a gas main or cable, the safest approach is simple: stop, clear, call, and document. The incident can have serious safety consequences and expensive knock-on costs, even if it looks minor at first.

If your business regularly excavates, it’s worth reviewing your risk controls and making sure your insurance is built for the real-world exposures of groundworks and construction.

Call to action

If you’re a UK contractor and want to sanity-check your liability cover for underground services, we can help you review your current setup and quote options. Call 0330 127 2333 or visit insure24.co.uk to speak to a specialist.